Quiz 1 - Chemical Kinetics: Rate Laws | Chemical Kinetics: Rate Laws
General Chemistry 2 - Quiz 1 - Chemical Kinetics: Rate Laws
What is the overall order of a reaction whose rate law is given by rate = k [A]2[B]?
This is a third-order reaction because the sum of the exponents in the rate law is 3 (2 for [A] and 1 for [B]). The order of the reaction is determined by summing the exponents of the concentration terms in the rate law expression.
Which method can be used to determine the order of a reaction with respect to a single reactant?
The method of initial rates involves measuring the initial rate of reaction for different initial concentrations of reactants. It is useful for determining the order of the reaction with respect to each reactant.
For a first-order reaction, how does the half-life depend on the initial concentration?
For first-order reactions, the half-life is independent of the initial concentration. This is a unique property of first-order kinetics.
Which of the following is characteristic of a zeroth-order reaction?
For a zeroth-order reaction, the rate is constant and does not depend on the concentration of the reactant.
Which equation represents the integrated rate law for a second-order reaction with respect to a single reactant A?
The integrated rate law for a second-order reaction is given by the equation 1/[A] = kt + 1/[A]0, linking the inverse concentration of A to time.
What is the half-life of a first-order reaction with a rate constant of 0.693 min-1?
The half-life of a first-order reaction (t1/2) is given by 0.693/k. As the rate constant k is 0.693 min-1, the half-life is 1.00 min.
How does the rate of a reaction change if the concentration of a reactant that appears to the first power in the rate law is tripled?
If the concentration of a reactant in a first-order rate law is tripled, the rate of the reaction increases by a factor of 3.
Given the data from a method of initial rates experiment, how would you find the order of the reaction with respect to one of the reactants?
In a method of initial rates experiment, one would plot initial rates versus initial concentrations of a reactant and fit the data to a power law to determine the order of reaction with respect to that reactant.
If a reaction that is first-order with respect to reactant A and second-order with respect to reactant B is carried out with both reactants initially at the same concentration, which will decrease in concentration faster as the reaction proceeds?
Reactant B, which is second-order, will decrease faster than reactant A, which is first-order, when both start at the same concentration because the rate of consumption for B is more sensitive to changes in its concentration.
In the context of radioactive decay, what does the phrase 'half-life is constant' mean?
For first-order reactions such as radioactive decay, the half-life is constant and does not depend on the initial amount of the substance present.